A prosthetic device, system and method is arranged to generate negative pressure inside a prosthetic socket. A pump mechanism is connected to a prosthetic foot and has a fluid chamber in fluid communication with the prosthetic socket during gait for drawing air from the prosthetic socket in step phase, and expelling air into the atmosphere in swing phase. The vacuum assisted suspension results in secure and intimate suspension as the negative pressure formed inside the prosthetic socket holds a residuum firmly to walls of the prosthetic socket. The vacuum is preferably formed at the distal area of the prosthetic socket, and sealed by a suspension liner having a seal component.